Wednesday's Ask the Experts: Mysterious black residue

Wednesday''s Ask the Experts question from a cleaning professional on the International Custodial Advisors Network (ICAN) "Ask the Experts" page: We recently did a strip and refinish on a daycare floor of about 10,000 sq. ft. We used Johnson’s Premia floor finish. Now, about two months later, the teachers are using a Swiffer wet cloth to wipe the floor daily and the cloth turns black. We dustmop and mop the floors daily with a neutral cleaner, and buff twice a month. The other day they called and said that they used a cloth diaper to wipe the floor and it turned black. So we went in, after the crew had cleaned, and used a cotton towel on the floor and it did not turn black. We followed with one of the Swiffers and it turned black. What do you think the black is?

The answer:

While everyone would be very impressed if I answered that the Polypropylene Glycol N-Butyl Ether and the Ethyl Alcohol solvents in the wet cloths are reacting with the Diethylene glycol monoethyl ether in the Premia to cause the black residue the cloths are picking up, I’m not a chemist and have no idea whether or not that is true. It could be the fragrance reacting with ... — Lynn E. Krafft, ICAN/ATEX editor